Refractory furnace for tobacco barns



Dec. 26, 1950 R. B. WlLLlAMSO N REFRACTORY FURNACE FOR TOBACCO BARNS 2 Sheets-Sheet 2 Filed June 5, 1947 me/1MM R. B, WILLIAMSON Patented Dec. 26, 1950 MEFRACI GRY EURNAGE F.OR TGBAGOO FBARNS Robert IB. `Wi11iamson, Bluefield, W. Va. `Application 3une5, 1947., Serial No; 7523500 (Cl. 11B-e1) Il Claims. .il

This invention relates to ffurnaces of the type which are put together from mrefabricated pant-s at the place of installation, rthis application being a continuation-impart `of :my pending appli-- cation Ser. No. 6.963507, utiled September :12,1946, now abandoned, for Refractory Furnace dior Tobacco Barns.

The general object of fthe invention is to provide a furnace r:particularlydesigned .for tobacco barns `for the hue-curing of tobacco, .made from precast refractory .un-its, each lof a weight and size to be easily `handled b y `one man, with adjunctive metal securing and spacing `members by which precise longitudinal alignment, gparal lelism `of the furnace side walls, length'and width of .the furnace, and rtightness of the joints lare automatically `obtained through the Ynature -of the construction, notwithstanding lack of par ticular skill `and experience Aon :the part `:of the labor assigned to the job of erecting ythe iurnace.

Other objects of the ,invention will appear as the following description of agnreferred and practical embodiment thereof proceeds.

In the drawings which accompany and form a part of the following specincation, and inwhich the same reference `characters designate identical parts:

Figure 1 is a perspective `view of u.a furnace embodying the inventive .concep`t, parts beingbrnken away;

Figure 2 is a front end elevation;

Figure 3 is a rear end elevation;

Figure 4 is a vertical section, taken along the line 4 4 of Figure 2 Figure 5 is a cross-section taken along the line 5-5 of Figure4;

Figure 6 is a cross-section taken along the line i-G of Figurel.

ln `the flue curing of Vtobacco it is `customary 'to place the tobacco in a `relatively tightly closed barn in which heat is applied to drive 'olf the moisture and set the color. `'These barnsfare provided with one or more furnaces and a system of flues or pipes leading therefrom to distribute the heat and carry off `the `products of combustion. Such furnaces have heretofore been made of brick, stone, `or metal, butin most instances lire brick has been employed. "It requires the services of a skilled mason properly to set `up `a stone or re `brick lfurnace. -Some attempts have been made A.to `construct `such furnaces lof precast refractory shapes, but `such attempts Alhave not heretofore been successful because `of the high degree of `skill needed to line up the walls of the furnace, which cannot usually be `found in the available fanmflabor.

The `present .invention provides `a furnace made of precast refractory members lin the minimum number of diversified forms, which uis self-aligning inthat `the `members'which.form the furnace alignment.

side walls are identical as to overall size rand shape, having the llcrm of rectangular prisms :so that they can be y.set upright in ,longitudinal se` quence upon -a level :slab or foundation. The side walls .may be considered .self-alignr1g, since the side .wall members have identically located longttudinal bores so that they can -beastrung `-upon longitudinal tie rods, assuring precise longitudinal :Meten .spacing plates .are provided with :equidistant lholes which can .be slipped on the lends of the :ftie vrods, 1assuring precise parellelism of the side walls. Sectional earch `members are also pnovided having the Ysame ,length as the side Wall members, .adapted .tolseat thereupon .to :form the roof of 4the furnace, the side wall members and arch 4members meeting in tongue .and Ygroove joints, assuring precise alignment when setting, and the arch members being of Gothic form, facilitating their mutual support. The completed `arch .is a .modified :catenary curve construction. It `iis understood that all .of the joints ,shall .be set .up in mortar.. preview .of the general principles of construction makes 4obvious the facility with which Vthe furnace ycan be accurately ,set up with no `more skill or experience than is possessed Jby .the average farmhandyman.

Referring now `in detail to the drawings, the numeral I represents a level 4Iznoured concrete slab or its equivalent, which is not apart of 'thefurnace structure., but serves as a foundation Atherefor. This slab is provided with ajhole 2, fopeningiupwardlyinto .the combustion chamber `o'f-the furnace .and downward into an underlying 'trench 3, indicate'd "in broken lines in 'Figures l and 4, which extends beyond the side of the slab. 'This is to receive a Stoker, the burner of which extends through .the 'hole 2 into the combustion chamber.

`Theifurnace comprises .the spaced side walls c and -5, each o'f which is built of a contiguous series of sidewall blocks 6. 'Each of these is identical 4'as a length, height and thickness, and all have the general contour of a rectangular prism. Each has upper and "lower 4parallel bores :1 and 8, identically located for each iblock 4in the median plane thereof, and Yextending longitudinally therethrough. Tiercds 9 passthrough the respective aligned upper and flower ibores of each series. Vertical metal "face plates 'I'D rest against the 'front `and rear ends `of 'the `respective side walls 4 pand 5. The 'face plates "I0 are `preferably rectangular in shape, and Aeach has a "pair of `holes -centered on =a line parallel Lwith the sides ofthe #face plate, Ato `register with the lrespective upper and lower bores 1 and 18. The ends Nuf `the tie rods -9 project through the holes Lin the Yface plates.

"The width of the furnace :determined and fixed by the metaltransverseplaftes 4I I, `of which there are four, itwo at 'the front and two atthe rear.

These have holes at their opposite ends and are identical as regards the distance apart of these holes. The ends of the tie rods 9 are passed through the holes in the transverse plates Il. The transverse plates are placed outside of the face plates I0. Nuts l2 screw upon the ends of the tie rods and are tightened against the transverse plates to draw the side wall blocks 6 into tight contact. The face plates le distribute the stresses imparted by the tie rods over an extensive surface of the outer ends of the terminal side wall blocks, and prevent the localizing of excessive strains which might cause crushing or cracking of the terminal side Wall blocks under conditions of expansion when the furnace is heated.

The side wall blocks are formed with a tongue on one side face and complementary groove on the other, so that adjacent blocks form a tongue and groove joint. It is understood that all of the ceramic pieces constitutingthe furnace will be set up with mortar joints.

The top faces of the side wall blocks are also grooved so as to form an interlocking joint with the arch members, which are to rest upon them. When the tie rods e are under tension, the pre-l cise parallel alignment of the furnace side walls and the rectangular shape of the furnace, becomes permanently xed. f

Some tobacco barns have one flue leading from the furnace, others have two, and large barns at times have three. In single flue barns connection is made to the` rear of the furnaceyolouble iiue barns generally connect to the nue barns utilize a rear connection as well as tc the right and left-handed side.

In order to make this furnace adaptable to any one of the conventional ilue systems, it has provisions for three iiue connections, one in the rear end, and one on each side near the rear. This is done by providing two rear side wall blocks in each row, designated by the reference character 6', withA semicircular recesses i3, whichmatch when the blocksl 6 are placed into adjacency, forming a complete circular opening le, one on each side. Two rear endwall blocks i5. are also provided, of the same size and shape as Vthe side wall blocks 6', and being similarly recessed to form a circular end opening ifi.. It will be observed that the recesses i3, and consequently the circular openings I4, are rabbeted on the outside, forming a bore II of relatively small diameter toward the inside, and a counter bore iii oflrelan tively large diameter toward the outside, thereby defining a collar i9. This lforms the end stop for a flue pipe 2Q, preventing the same from projecting into the heat chamber of the furnace, the collar I9 protecting the pipe 2d from contact by the flames, preventing it from becoming red hot or eventually burned out, and being a re hazard. If the barn construction is such that only one or two flue connections are made to the furnace, two plugs 2l are furnished of such size and shape as to fit into the large bore le and` rest against the collar I9. These are selectively placed in such ue openings as are not to be employed, beingset up in mortar. f

A pair of rectangular posts 22 of the same height as the rear end wall blocks i3 are arranged vertically within the side walls at the front end, contiguousto the respective side walls and flush with the front ends of the side walls. These dene between them a restricted rectangular open-V ing 23, into the furnace chamber. Y

. vIdentical arch shaped filler pieces ,2e and 25 at the front and rear rest respectively upon the tops of the posts 22 and upon the rear end blocks I B and close the end spaces subscribed by the arch members.` The filler pieces are set ush with the front and rear faces of the side walls.

The roof of the furnace is constituted by arch members 26, each being of the same length as the side wall blocks 6, and of the same thickness. To ease the burden of lifting heavy and unwieldy parts, each arch member is preferably made in four sections, two on each side. A base section 2l'l has a tongue on one face which ts into the groove in side wall 5 and a groove on the opposite face. This block likewise is used in the peak of the arch on the opposite side. A base section 3| has a tongue on each complementary face to fit into the groove of side wall block 6 and the groove of peak section. A peak section 28 with a tongue on one face and groove on the complementary face completes the closure of the arch.

In erecting the furnace, the rear ller piece 25 is put in place and the rearmost arch sections supported upon it, preferably with their grooved side faces toward the front. The sections of the next adjacent arch member are then put in place with their tongued side faces in juxtaposition to the grooved side faces of the sections of the rst erected arch member, being supported by the interlocking of the complementary tongues and grooves. Before the foremost arch member is erected the front filler piece 24 is put in place. rEhe Gothic shape of the arch members enables each side of the arch to mutually support the other more eiiciently than in the case of a circular arch.

A row of fire bricks 29 rests upon the slab I and extends across the furnace chamber at an intermediate point in its length, forming the rear wall of the combustion chamber and having a height less than that of the side walls 4 and 5 so that the combustion products can pass over it freely. It constitutes a barrier to confine the ashes to the forward part of the furnace.

While dimensions are not vital to the inventive concept, it is one of the purposes of the invention to make the refractory members of such size and weight that they can be handled by one man. In the exemplary embodiment herein illustrated, the side wall members are Jtwelve inches long, eighteen inches high and four inches thick. The size of the other refractory parts are pro-Y portioned to these dimensions and all are within the limits of one-man manipulation. It is contemplated that the joints between all the refractory members shall be set up with mortar, to pre vent nre and gas leakage.

Figures l and 4 show that the front transverse plates li are onset from the plane of the front of the side walls by a distance equal to the thickness of the intervening front face plates it. A metal door 3d, of slightly less thickness than the front face plates, slides against the front faces of the posts 22 and iller members li, being retained by the transverse plates le. It may be lifted or removed for inspection of the combustion chamber, or for removal of the ashes.

While the drawing shows furnace as set up for installation of a Stoker, it is contemplated that this same type of furnace could, by the insertion of grates in the front end, be adapted to the use of wood, coal, coke, petroleum, pitch or other solid fuel fired by hand. Likewise, an oil or gas burner could be used as a heat source when such fuel is available.

From the above description it is obvious that the subject furnace can be put together in the barn by a workman of very limited skill and experience, since the provision of the tie rods and transverse spacing plates determines the precise alignment and rectangular size and shape of the furnace base, forming a rigid integrated structure which serves as a guide for the correct positioning of the front post members, rear end wall members, ller members and arch members. A furnace of this construction is tied together by metallic bonds so that it cannot become breached or fall apart in the manner common to locally built brick or stone furnaces, so that nre hazard from this cause is altogether eliminated.

What I claim as my invention is:

l; Furnace comprising spaced parallel side walls, each consisting of a row of contiguous refractory members of uniform width and uniform height, tie rods extending through said rows, transverse spacing plates at the front and rear ends of said side walls extending between the tie rods of the respective side walls, through which the ends of said tie rods extend, nuts for tensioning said tie rods to bring said side walls and spacing plates into a rigid rectangular unit, refractory end wall members of the same height as said side wall members fitted between said side walls at the rear flush with the rear ends theren of, vertical posts of the same height as said end wall members, between said side walls at the front, contiguous thereto and flush with the front end thereof, defining a reduced opening at the front of said furnace, refractory arch members forming the roof of said furnace, each having the same width as said side wall members, bridging the space between said side walls and seated thereupon, the joint between said side wall members and arch members including interdigitating tongues and grooves formed on said members.

2. Furnace as claimed in claim 1, said arch members being each formed of a plurality of contiguous sections having tongue and groove points.

3. Furnace comprising spaced parallel side walls, each consisting of a row of contiguous refractory members of uniform Width and uniform height, tie rods extending through each row, transverse spacing plates extending between the respective side walls at their ends, through which plates the ends of said tie rods extend, vertical face plates at the front and rear ends of said side walls through which said tie rods pass, said front face plates being between the ends of said side walls and the front transverse spacing plates, end wall members of the same height as the side wall members fitted between said side walls at the rear and iiush with the rear ends thereof, vertical posts of the same height as said side wall members between said side walls at the front, contiguous thereto and flush with the front ends thereof defining a restricted opening at the front of said furnace, refractory arch members having the same width as said side wall members bridging the space between said side walls and seated thereupon, the joint between said side wall members and arch members including interdigitating tongues and grooves formed on said members, refractory ller members upon said posts at the front and said end wall members at the rear, closing the respective spaces between the tops of said posts and the tops of said end wall members and the terminal arch members, and a door slidable vertically between said front transverse spacing plates and the refrac- (iii tory front of said furnace, across said restricted opening.

4. Furnace comprising spaced parallel side Walls, each consisting of a row of contiguous refractory members of uniform width and uniform height, tie rods extending through each row, transverse spacing plates extending between the respective rows at the ends of said side walls through which the ends of said tie rods extend, nuts for tensioning said tie rods to bring said side walls and spacing plates into a rigid rectangular unit, refractory end wall members fitted between said side walls at the rear and flush with the rear ends thereof, said end wall members having their contiguous faces provided with matching semi-circular depressions forming a circular flue opening.

5. Furnace comprising spaced parallel side walls, each consisting of a row of contiguous refractory members of uniform width and uniform height, tie rods extending through each row. front and rear transverse spacing plates extending between the tie rods of the respective rows at the ends of said side walls through which the ends of said tie rods extend, nuts for tensioning said tie rods to bring said side walls and spacing plates into a rigid rectangular unit, refractory end wall members fitted between said side walls at the rear and fiush with the rear ends thereof, a pair of adjacent side wall members in each side wall near the rear and a pair of said end wall members, each pair of said members having their contiguous faces provided with matching semi-circular depressions forming a circular flue opening, alternatively usable, and refractory plugs less in number than the number of flue openings, for closing any of said ue openings which are not to be used.

6. Furnace comprising spaced parallel side walls and an intervening rear end wall, said walls being formed of contiguous refractory members of uniform height, a pair of said refractory members being formed on adjacent sides with matching semi-circular depressions dening a circular flue opening, said opening being of stepped diameters, the part of larger diameter facing outwardly, the part of smaller diameter forming a collar functioning as astop to limit the incursion of a flue pipe fitting within the part of large diameter.

7. Furnace as claimed in claim 1, including a refractory filler upon said posts at the front, bridging said posts and closing the space between the top of said posts and the adjacent terminal arch members, and a similar filler member at the rear upon said end wall members, closing the space between the tops of said end wall members and the terminal arch members adjacent thereto.

ROBERT B. WILLIAMSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 301,864 Coulter July 15, 1884 682,109 Murray Sept. 3, 1901 720,163 Lockwood Feb. 10, 1903 1,312,916 Lillie Aug. 12, 1919 1,694,393 Nash et al Dec. 11, 1928 1,730,289 Parker Oct. 1, 1929 2,171,275 Morrison Aug. 29, 1939 2,181,338 Moran Nov. 28, 1939 

